Interventions with children and parents to improve physical activity and body mass index: a meta-analysis.

OBJECTIVE: Examine the effect of interventions with parents and children on children's physical activity and body mass index (BMI). DATA SOURCE: Computerized searches for intervention studies published between 1990 and 2011 used multiple ProQuest databases, including unpublished dissertations and theses to minimize publication bias. STUDY INCLUSION AND EXCLUSION CRITERIA: English-language, intervention-testing studies of children, parents, or families with outcomes of physical activity or BMI were retrieved from peer-reviewed journals, dissertations, and theses. Eliminated studies had no control or comparison group; had no continuous outcome variable; had no physical activity/exercise and/or BMI as outcomes; or had incomplete statistics necessary for meta-analysis (means, standard deviations, or confidence intervals). DATA EXTRACTION: Twenty-one studies met inclusion criteria. Quality criteria were control group, objective outcome variable measure, clarity of variable definitions, and number and reason for subject withdrawal. DATA SYNTHESIS: Meta-analysis on the raw difference of means estimated mean weighted effect size (MWES) assessed dispersion of effects and computed a summary effect.
RESULTS: MWES for interventions with parents and children on physical activity (Z = 2.92; confidence interval [CI] = .09 to .48; p = .002) and on BMI for interventions with children alone (Z = -2.10; CI = -.16 to -.01; p = .02) was significant.
CONCLUSION: A significant effect on physical activity but not on BMI was found when interventions included both parents and their children.